CVE-2016-9962
Description
The runc component used by docker exec feature of docker allowed additional container processes to be ptraced by the pid 1 of the container. This allows the main processes of the container, if running as root, to gain low-level access to these new processes during initialization. An attacker can, depending on the nature of the incoming process, leverage this to elevate access to the host. This ranges from accessing host content through the file descriptors of the incoming process to, potentially, a complete container escape by leveraging memory access or syscall interception.
Mitigation
On Red Hat systems with SELinux enabled, the dangers of even privileged containers are mitigated. SELinux prevents container processes from accessing host content even if those container processes manage to gain access to the actual file descriptors.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | 6.4 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | High | High | N/A |
| Privileges Required | High | High | N/A |
| User Interaction | None | None | N/A |
| Scope | Changed | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
NVD: CVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Acknowledgements
Red Hat would like to thank the Docker project for reporting this issue. Upstream acknowledges Aleksa Sarai (SUSE) and Tõnis Tiigi (Docker) as the original reporters.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
